This translation of Mendel's Versuche über Pflanzen-Hybriden (Abh. Naturf. ver. Brünn, v. 4, 1866) by the Royal Horticultural Society, London, appeared in their Journal, v. 26, p. 1, 1901, from which it was reprinted in Castle, W. E. Genetics and eugenics, 1916 with foot-notes and minor changes suggested by Prof. W. Bateson